As early as elementary school, girls are more likely than boys to possess self-evaluative mechanisms that may heighten vulnerability to depressive and anxiety symptoms. Consequently, sex differences in these mechanisms during elementary school may play a key role in sex differences in depressive and anxiety symptoms. There is little empirical evidence, however, as to development of these mechanisms. The major goal of the proposed research is to examine the distal and proximal social-psychological processes involved in the development of sex differences in self-evaluative mechanisms. Of central concern is the role of parental gender socialization. Based on several lines of research, it is hypothesized that culturally-held gender stereotypes may cause parents to be more controlling in certain behavioral domains with girls than with boys. This pattern of gender socialization is expected to lead girls to be more likely than boys to possess self-evaluative mechanisms that heighten vulnerability to depressive and anxiety symptoms. These hypotheses, as well as hypotheses about the role of social-cognitive developmental factors in the development of sex differences in self-evaluative mechanisms and consequent depressive and anxiety symptoms, will be addressed in two study sets using a combination of correlational and experimental methods as well as cross-sectional and longitudinal designs. The results of the proposed research will elucidate the development of not only sex differences in self-evaluative mechanisms and consequent depressive and anxiety symptoms but also these phenomena in general. Hence, the research will provide knowledge which may be used to create intervention programs that prevent depressive and anxiety symptoms in children of both sexes.